The route distribution problem of multi-service optimization in Synchronous Digital Hierarchy (SDH) Transmit Network can be qualitatively described as: in case of network topology, i.e. structure of nodes and links, and service matrix table are provided, it is required that resource of services carried by each link do not exceed the total amount of the network resource, the network resource is occupied to be the least, and network load is balanced, while distributing route for each service. Up to the present, there is no method to solve this problem. However, the most approximate applied scheme is the route distribution method in a Dense Wavelength Division Multiplexing (DWDM) optical network. In this scheme, in order to implement route distribution, heuristic algorithm is often adopted. The principle of heuristic algorithm is: in term of a certain routing strategy, such as shortest route method, calculating the initial solution of service route; then according to whole network resource such as utilized state of wavelength, recalculating the route of a partial services until the service indicator reaches expectation value, or until the calculated result reaches convergence, or until the calculation is repeated for certain times, then obtaining an acceptable solution.
In addition, genetic algorithm or neural network algorithm are adopted in a DWDM network sometimes for routing solution. However, a DWDM network belongs to general Mesh Network, which is a grid network with simple structure and only has interconnection between nodes rather than such structure as rings. Therefore, the heuristic algorithm applied in DWDM network based on such Mesh Network only considers simple connection between nodes, without considers specific network topology feature such as cross connection etc. Therefore, there is great uncertainty of the heuristic algorithm for network multi-service optimization effect. Furthermore, the genetic algorithm and the neural network algorithm are only applicable under the condition of small-scale network and simple constraint. With the network scale growing, especially when number of network nodes exceeds 50, these methods not only need a pretty long time for a solution, but also can not satisfy the time efficiency requirement of service network, and can not obtains the optimum solution under most circumstance.